1. Field of the Invention
The present invention relates to a spacer for a windshield wiper, and more particularly to a spacer for a windshield wiper which is provided with retaining means for preventing the spacer from being separated from an associated element of the windshield wiper upon assembling the elements of the windshield, while increasing the clamping force of the spacer, thereby minimizing the clearance defined between the spacer and the associated element.
2. Description of the Related Art
As well known, a windshield wiper for a vehicle is adapted to wipe raindrops and snow attached to the front windshield of the vehicle, thereby ensuring a desired forward visibility during the running of the vehicle. Such a windshield wiper includes a metal yoke assembly, and a blade rubber assembly coupled to the metal yoke assembly.
In such a windshield wiper, spacers are used as connecting means for firmly connecting the constitutive elements of the metal yoke assembly in order to allow the windshield wiper to operate without generating vibrations.
Referring to FIGS. 5a and 5b, a windshield wiper is illustrated in which conventional spacers are coupled among the constitutive elements of a metal yoke assembly included in the windshield wiper, respectively.
As shown in FIGS. 5a and 5b, a primary yoke member 300 is pivotably coupled to a wiper arm 200 by a spacer 100. A pair of secondary yoke members 400 are pivotably coupled to both ends of the primary yoke member 300 by other spacers 100, respectively. A blade rubber assembly including a blade rubber element 500 is coupled to the secondary yoke members 400.
The wiper arm 200 has an inverted-U-shaped coupling end defining a spacer receiving space 210 while having rivet holes 220 at both sides of the spacer receiving space 210. A rivet 600 extends through the rivet holes 220.
Each spacer 100 has an inverted-U-shaped structure including an upper panel 110, and a pair of side panels 120 and 120a extending downwardly from opposite lateral ends of the upper panel 110. A receiving space 130 is defined by the upper panel 110 and the side panels 120 and 120a. Through holes 121 corresponding to the rivet holes 220 are centrally formed at the side panels 120 and 120a. Annular protrusions 140 are inwardly protruded from respective through holes 121 such that they face each other.
The primary yoke member 300 has, at its central portion, an inverted-U-shaped structure having through holes 310 respectively corresponding to the through holes 121 of the spacer 100 in which the central portion of the primary yoke member 300 is to be received. Similarly, each secondary yoke member 400 has, at its central portion, an inverted-U-shaped structure having through holes respectively corresponding to the through holes of the spacer 100 in which the central portion of the secondary yoke member 400 is to be received.
In the process of assembling the above mentioned elements of the windshield wiper, the primary yoke member 300 is first fitted, at its central portion, in the receiving space 130 of the associated spacer 100 such that the protrusions 140 of the spacer 100 are received in the through holes 310 of the primary yoke member 300. The spacer 100 assembled with the primary yoke member 300 is then fitted in the spacer receiving space 210 of the wiper arm 200 such that the rivet holes 220 are aligned with the through holes 121 and 310 of the spacer 100. Thereafter, the rivet 600 is inserted through the aligned holes 220, 121, and 310.
Thus, the primary yoke member 300 is pivotably coupled to the wiper arm 200 in a state in which the spacer 100 is interposed between the wiper arm 200 and the primary yoke member 300. In the same manner, the secondary yoke members 400 can be pivotably coupled to the primary yoke member 300.
The side panels 120 and 120a of the spacer 100 should be forcibly moved away from each other to widen the space defined therebetween when the primary yoke member 300 is fitted in the spacer 100, in order to prevent the fitting operation of the primary yoke member 300 from being obstructed by the protrusions 140. However, although the force applied to the side panels 120 and 120a is released, the side panels 120 and 120a are incompletely recovered to their original state, thereby forming a clearance between the spacer 100 and the primary yoke member 300. For this reason, vibrations are generated during an operation of the windshield wiper, so that it is impossible to effectively remove the moisture attached to the front windshield of the vehicle.
In addition to the formation of the clearance, the conventional windshield wiper has another problem in that the clamping force of the side panels 120 and 120a in the primary yoke member 300 is small because the side panels 120 and 120a are thin. Furthermore, the protrusions 140 of the spacer 100 may be easily separated from the through holes 310 of the primary yoke member 300. For this reason, the primary yoke member 300 may be downwardly separated from the spacer 120 when an external force is applied to the spacer 10 or primary yoke member 300 during the assembling process. Where an automatic riveting process is used, the spacer 120 assembled with the primary yoke member 300 may be separated from the primary yoke member 300 due to an impact or vibration generated during a procedure for moving the assembly to a stage for carrying out the riveting process. As a result, the efficiency of the assembling process is degraded, thereby reducing the productivity of the windshield wiper.
The present invention has been made in view of the above mentioned problems, and an object of the invention is to provide a spacer for a windshield wiper which is provided with retaining means capable of preventing the spacer from being separated from a primary or secondary yoke member due to an external impact applied to the spacer.
Another object of the invention is to provide a spacer for a windshield wiper which is provided with retaining means capable of easily assembling the spacer to a desired element of the windshield wiper while firmly maintaining the assembled state of the spacer.
Another object of the invention is to provide a spacer for a windshield wiper which is provided with retaining means capable of increasing the clamping force of the spacer to be assembled with a primary or secondary yoke member, thereby minimizing the clearance formed between the spacer and the primary or secondary yoke member.
In accordance with the present invention, this object is accomplished by providing a spacer of a windshield wiper for a vehicle including an upper panel, a pair of side panels extending downwardly from opposite lateral ends of the upper panel while defining a receiving space therebetween, the side panels being centrally formed with through holes, respectively, and annular protrusions protruded, toward each other, from the side panels around the through holes, and adapted to be fitted in through holes formed at an element of the windshield wiper to be assembled with the spacer, respectively, wherein each of the protrusions has a tapered structure having a diameter gradually reduced toward a free end of the protrusion, while having retaining means adapted to retain the protrusions in a state of being fitted in the through holes of the windshield wiper element, the retaining means comprising an annular step formed at the free end of each of the protrusions, and a plurality of slits formed at the annular step.
Preferably, the step has a vertical surface at an end thereof spaced away from the free end of the protrusion associated therewith, and an inclined outer surface.
Preferably, each of the protrusions has an inclined inner surface having a diameter gradually reduced toward the free end of the protrusion.